Here's a nice post and response on 3 Things to Unlearn from School:
1) The importance of opinion.
2) The importance of solving given problems.
3) The importance of earning the approval of others.
And from the response:
4) Parroting back something even though you don't understand it.
I agree fairly well, especially with 1 and 3. Your opinion matters much less than what the consequences would be if your opinion were widely adopted or implemented. To determine the consequences, you need to have factual and empirical backing, not just an "I feel..." statement. Most of the opinions on a college campus are of the "I feel..." variety whether the speaker knows it or not. I addition, what you think is much less important than what is.
Something else that bothers me in that vein is confusing opinions with policy prescriptions. If I say that I don't like to hunt, it does not necessarily follow that I want to ban hunting, I just don't like to hunt.
As regards 3, seeking the approval of others can lead you into repeating the company line as opposed to offering new ideas or rocking the boat when the boat needs to be rocked. I'm not sure how you combat that one without fundamentally altering the way grading is done and most people don't develop a taste for being the devil's advocate or for being hated.